Introduction

The Calcitonin receptor plays an important role in the regulation of calcium and phosphate metabolism. It binds the peptide hormone Calcitonin, wich was named for its ability to reduce the blood calcium level.

Calcitonin (CT) is a 32 amino acid peptide cleaved from a larger prohormone. It contains a single disulfide bond, which causes the amino terminus to assume the shape of a ring. All members of the calcitonin family of peptides share this special secondary structure. Specific high-affinity receptors on the cell surface, mainly of osteoclasts mediate CT action. The first gene of the Calcitonin Receptor (CTR) has been cloned in 1991. CTR is a member of the seven-transmembrane, G protein-coupled receptor (GPCR) family. It is homologous to GPCRs in family "B" which typically recognizes regulatory peptides like secretin, glucagons etc. Interestingly, the specificity of CTR and CTR-like receptors (CRLRs) could be changed through receptor activity modifying proteins (also called Calcitonin-receptor-like receptor activity-modifying proteins or RAMPs). It is shown that Calcitonin Receptor-Like Receptor (CRLR) can function as either a CGRP receptor or an ADM receptor, depending upon which members of RAMP1-3 are expressed.

Interaction between CRLR and RAMP1 leads to receptors sensitive to CGRP, whereas the interaction with RAMP2 or 3 creates a receptor sensitive to adrenomedullin. The interaction between CTR and RAMP1 or RAMP3 gives however rise to an amylin sensitive receptor.

OriGene Technologies offers a panel of antibodies to the different members of the CTR family: CTR, CTLR, RAMP1, RAMP2 and RAMP3 can be detected by immunological methods like immunohistochemistry, Western blotting or ELISA.